BACKGROUND An excess of weight including obesity have reached epidemic rates in all age groups, both in developed and developing countries. It is notable that overweight children and adolescents have a higher likelihood of becoming obese adults and to present health-related problems early in life. OBJECTIVE [corrected] To verify associations of the lipid and hematological profiles with adiposity in obese adolescents beginning multidisciplinary weight loss therapy. METHODS This cross-sectional study was conducted with 85 adolescents of both genders, aged 12-19 years (Tanner staging 3 or 4) and body mass index greater than the 95(th) percentile. The sum of the triceps, subscapular and calf skinfolds and the waist circumference were used to estimate adiposity. Blood samples were collected from all patients after overnight fasting to analyze blood lipids (total cholesterol, high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein and triglycerides), blood sugar and the hematological profile (hemoglobin, platelets and red blood cells). The Kolmogorov-Smirnov test and Spearman and Pearson correlation coefficients were used for statistical analysis with significance set for p-values ≤ 0.05. RESULTS There were statistical differences between genders for red blood cells (p-value = 0.000), hemoglobin (p-value = 0.000) and platelets (p-value = 0.002). Positive correlations were found for red blood cells (p-value = 0.031) and hemoglobin (p-value = 0.024) with waist circumference. There was a negative correlation between hemoglobin and the sum of skinfolds (p-value = 0.022). CONCLUSIONS The results demonstrate an association between the lipid and hematological profiles and body adiposity in obese adolescents thus reinforcing the importance of treating obese adolescents early to prevent health related problems in adult life.